It is well known in the automotive door hinge art to provide a door check mechanism in combination with a door hinge assembly to control movement of the vehicle door when moving between an open position and a closed position. Such door check mechanisms may be used independently and additionally to the door hinge assemblies, or the door check mechanisms may be integral with the door hinge assembly. It is more efficient to utilize a check mechanism that is integral with the door hinge assembly as the hinge and integral check assembly typically requires less parts and less assembly time than utilizing the check mechanism independently of the hinge assembly.
Several prior art designs have integrated the door check mechanisms into the hinge assembly but such devices are either complex in design or non-durable over the operational life of the assembly. Such complex designs are disclosed in U.S. Pat. No. 3,370,317 to Marchione and U.S. Pat. No. 3,931,664 to Nakano, et al. which both disclose rollers engaging a torsion bar or check spring. These devices typically require a significant amount of lubrication to facilitate the long rolling contact of the rollers with the check spring.
Another common design for integrating the check mechanism with the hinge assembly provides a bent over strike tang on the door portion of the hinge that slides along and compresses a leaf spring member carried on the body portion of the hinge to control movement of the door when moving between the open position and the closed position. Again, this design requires lubrication for easy and quiet operation of the assembly. Also, when the door and assembly is in the open position, the strike tang maintains contact with the leaf spring thus applying a constant stress on the strike tang. Such stress over time reduces durability and reliability as the cyclic stress begins to wear certain components of the hinge and check assembly. For example, the bent over strike tang often comprises a nylon roller that rolls along the leaf spring. These rollers typically wear due to the cyclic life stresses that are applied to the roller by the roller contacting the leaf spring.
Typically, the strike tangs are pivotally connected to a base portion of the hinge by a pivot pin. A bronze bushing is commonly utilized to separate the pivot pin from the assembly, so that the assembly will freely rotate about the pivot pin without wearing the pivot pin. The pivot pin provides for the pivotal movement of the door, and the body portion of the hinge supports the load of the door in the axial direction of the pivot pin. The leaf spring has a contoured planar shape mounted in a plane generally parallel to the pivot pin, and the roller has a rotational axis parallel to the pivot axis. The roller is pivoted rotationally about the pivot pin to perpendicularly engage the leaf spring. When the roller engages the leaf spring a lateral force is applied to the pivot pin and bushing. The lateral force causes the bushing to wear and deform at the point at which the strike tang is connected to the base of the hinge assembly. Such wear and deformation of the bushing leads to performance degradation of the hinge and check assembly and shortens the useful life of the hinge and check assembly.
Such designs are also limited as to whether the assemblies may be utilized on the top or bottom portion of the vehicle door. For example, the roller and leaf spring design typically provides a pair of mounting apertures in the base to connect the base of the hinge assembly to the vehicle body. One of the apertures lies directly under the leaf spring, and therefore, a rigid fastener must be assembled to the base before the leaf spring is connected to the base. This means access must be given through the vehicle body in order to secure the fastener to the vehicle body since the head of the fastener is inaccessible under the leaf spring. Consequently, location of the hinge assembly may be limited as access through the vehicle body may not be possible, such as trying to gain access through an instrument panel of the vehicle in order to utilize the hinge assembly on a front, top hinge of a vehicle door.
Generally, most hinge and integral check assemblies are fabricated from heavy gauge steel to provide strength to the assembly. Such heavy gauge steel adds weight to the vehicle, and therefore reduces fuel economy. Several machining and pressing operations are typically required causing increased tolerances and reduced repeatability leading to degradation of the performance of the assemblies.